A Novel Large-Scale, Multilayer, and Facilely Aligned Micropatterning Technique Based on Flexible and Reusable SU-8 Shadow Masks

A simple method to fabricate flexible, mechanically robust, and reusable SU-8 shadow masks is demonstrated. This shadow mask technology has high pattern flexibility as various shapes with different dimensions can be created. The fabricated shadow masks are characterized in terms of the resolution, reusability, and capability of multilayer surface micropatterning. Fabrication of a new plastic photomask for the exposure process simplifies the shadow mask fabrication process and results in higher resolution in the shadow mask structures compared to the commercial chromium photomasks. For the multilayer surface micropatterning technology, a simple and fast alignment technique based on SU-8 pillars and without usage of any microscopic tools is reported. This unique method leads to a less complicated alignment process with the alignment accuracy of approximate to 2 mu m. The proposed shadow mask technology can be easily employed for wafer-scale micropatterning process. The capability of fabricated SU-8 shadow masks in micropatterning on polymer thin films is evaluated by fabricating metallic contacts on poly(3,4-ethylenedioxythiophene) samples and electrical characterization.